Abstract: Objective To investigate the clinical characteristics of a group of cases with orbital apex syndrome caused by non-specific inflammation. Design Retrospective case series. Participants 15 patients(16 eyes) with orbital apex syndrome caused by non-specific inflammation of orbital apex in Beijing Tongren Hospital and Beijing Puren Hospital from June 2016 to May 2019. Methods The clinical symptoms, physical signs, ophthalmic imaging, laboratory examination, hormone treatment effect and prognosis were reviewed. Main Outcome Measures The clinical symptoms and signs, orbital and head CT, MRI image features. Results Of the 15 patients, 8 were male, with an average age of (53±16) years. 14/15 patients were attacked by monocular. The lesion of all cases was confined to the orbital apex, 7 of which were both involved in the cavernous sinus. Periorbital pain occurred in the eyebrow arch or radiated to the zygomatic temporal part, orbital apex syndrome gradually appeared after the pain. The irregular solid lesions of orbital apex in orbital MRI showed equal T1WI and equalT2WI signals, which could be enhanced uniformly. The patients who were finally diagnosed as non-specific orbital inflammation were treated with systemic and /or ocular local hormone treatment. The symptoms of 15 patients were totally relieved, the periorbit pain of 14 eyes (87.5%) were completely disappeared. The blepharoptosis of 13 eyes (81.3%) were relieved, and ocular movement and diplopia of 11 eyes (68.8%) were improved. All the lesions in orbital MRI shrinked after 3 months hormone treatment. The recovery of visual function, however, was unsatisfactory. The vision of 8 eyes (50%) had no improvement, 2 eyes (12.5%) relapsed during the period of follow-up. Conclusion The orbital apex syndrome induced by non-specific inflammation is characterized by local ocular pain and oculomotor disturbance in early stage, and then the visual impairment happened quickly. Clinical manifestations and neuroimaging examination are the main diagnostic basis. Systemic and/or local hormone therapy can effectively improve eye movement disorders and pain. But the recovery of visual acuity is difficult and the recurrence is possible. (Ophthalmol CHN, 2021, 30: 56-61)

Key words: orbital apex syndrome, idiopathic orbital inflammatory pseudotumor